A table saw is a power tool used to cut a work piece to a desired size or shape. A table saw includes a work surface or table and a circular blade extending up through the table. A person uses a table saw by placing a work piece on the table and feeding it into contact with the spinning blade to cut the work piece to a desired size. The table saw is one of the most basic machines used in woodworking.
If a work piece shifts slightly during a cut, it is possible for the teeth at the back of the blade to catch an edge of the work piece as the teeth on the spinning blade rise out of the table. The blade can then lift, spin and kick the work piece back toward the user at a high speed. This situation is called kickback, and it can potentially cause serious injury to the user. A riving knife or spreader can be mounted in a table saw to prevent the work piece from shifting and thereby help to prevent kickback. A riving knife or spreader is basically a thin, planar metal plate with a thickness slightly less than the kerf of the blade (i.e., the width of the teeth of the blade). The riving knife or spreader is mounted in the saw behind but relatively close to the blade. Typically, the riving knife or spreader is curved along a front edge to match the profile of the blade. As the work piece moves past the blade, the riving knife or spreader fits within the newly formed cut in the work piece and helps keep the work piece moving along a straight path without shifting or rotating.
This document describes mounting systems for securing a riving knife or spreader in a table saw. Specifically, this document describes clamping systems to mount a riving knife or spreader in a table saw, including in a jobsite table saw.